A Java JTable example, with AbstractTableModel, JScrollPane, isCellEditable, getColumnName, getValueAt

The following Java source code comes from Sun Microsystems, and shows a JTable example, including the use of an AbstractTableModel, a JScrollPane, and methods like:

• isCellEditable
• getColumnName
• getValueAt
• getRowCount
• setPreferredScrollableViewportSize

Here’s the example Java JTable source code:

/**
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

/**
 * TableDemo.java is a 1.4 application that requires no other files.
 */

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import java.awt.Dimension;
import java.awt.GridLayout;

/**
 * TableDemo is just like SimpleTableDemo, except that it uses a custom
 * TableModel.
 */
public class TableDemo extends JPanel {
  private boolean DEBUG = false;

  public TableDemo() {
    super(new GridLayout(1, 0));

    JTable table = new JTable(new MyTableModel());
    table.setPreferredScrollableViewportSize(new Dimension(500, 70));

    //Create the scroll pane and add the table to it.
    JScrollPane scrollPane = new JScrollPane(table);

    //Add the scroll pane to this panel.
    add(scrollPane);
  }

  class MyTableModel extends AbstractTableModel {
    private String[] columnNames = { "First Name", "Last Name", "Sport",
        "# of Years", "Vegetarian" };

    private Object[][] data = {
        { "Mary", "Campione", "Snowboarding", new Integer(5),
            new Boolean(false) },
        { "Alison", "Huml", "Rowing", new Integer(3), new Boolean(true) },
        { "Kathy", "Walrath", "Knitting", new Integer(2),
            new Boolean(false) },
        { "Sharon", "Zakhour", "Speed reading", new Integer(20),
            new Boolean(true) },
        { "Philip", "Milne", "Pool", new Integer(10),
            new Boolean(false) } };

    public int getColumnCount() {
      return columnNames.length;
    }

    public int getRowCount() {
      return data.length;
    }

    public String getColumnName(int col) {
      return columnNames[col];
    }

    public Object getValueAt(int row, int col) {
      return data[row][col];
    }

    /**
     * JTable uses this method to determine the default renderer/ editor for
     * each cell. If we didn't implement this method, then the last column
     * would contain text ("true"/"false"), rather than a check box.
     */
    public Class getColumnClass(int c) {
      return getValueAt(0, c).getClass();
    }

    /**
     * Don't need to implement this method unless your table's editable.
     */
    public boolean isCellEditable(int row, int col) {
      //Note that the data/cell address is constant,
      //no matter where the cell appears onscreen.
      if (col < 2) {
        return false;
      } else {
        return true;
      }
    }

    /**
     * Don't need to implement this method unless your table's data can
     * change.
     */
    public void setValueAt(Object value, int row, int col) {
      if (DEBUG) {
        System.out.println("Setting value at " + row + "," + col
            + " to " + value + " (an instance of "
            + value.getClass() + ")");
      }

      data[row][col] = value;
      fireTableCellUpdated(row, col);

      if (DEBUG) {
        System.out.println("New value of data:");
        printDebugData();
      }
    }

    private void printDebugData() {
      int numRows = getRowCount();
      int numCols = getColumnCount();

      for (int i = 0; i < numRows; i++) {
        System.out.print("    row " + i + ":");
        for (int j = 0; j < numCols; j++) {
          System.out.print("  " + data[i][j]);
        }
        System.out.println();
      }
      System.out.println("--------------------------");
    }
  }

  /**
   * Create the GUI and show it. For thread safety, this method should be
   * invoked from the event-dispatching thread.
   */
  private static void createAndShowGUI() {
    //Make sure we have nice window decorations.
    JFrame.setDefaultLookAndFeelDecorated(true);

    //Create and set up the window.
    JFrame frame = new JFrame("TableDemo");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Create and set up the content pane.
    TableDemo newContentPane = new TableDemo();
    newContentPane.setOpaque(true); //content panes must be opaque
    frame.setContentPane(newContentPane);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });
  }
}